Zinc is a transition metal that is also an essential mineral for both humans, animals, and plants. Zinc is important to the human body for many reasons; it aids the immune system, promotes cell growth and division, sleep, mood, skin and eye health, insulin regulation, and even male sexual function.
Its immune benefits have been shown to have the strongest effect of all the vitamins and minerals, due to its role in the T-cells. These cells recognize and fight off infection, and low levels of zinc lead to a reduction and weakening of these cells. Zinc has also shown to reduce the duration and severity of the common cold, especially when taken at the first sign of symptoms.
Zinc is critically important for human health. Infants and adolescents need zinc for cell division, which is occurring at a rapid pace because of their rapid growth during this phase of life. Adults also need zinc because immune function diminishes with age and zinc plays a highly important role in helping support the immune system. Its role in skin, hair, and nails has also been recognized as it accelerates the growth of skin cells; this is especially useful for healing a variety of cuts and wounds. It soothes skin tissue with its anti-inflammatory properties, particularly after any skin irritation such as sunburns or rashes.
Zinc is also found in high concentrations in the retina of the eyes and with age, the concentration of zinc decreases leading to age-related macular degeneration. It may also help prevent night blindness and the development of cataracts.
One of zinc’s most important role is to help maintain reproductive health. Zinc increases fertility in men by protecting the prostate gland from infection and maintaining sperm count and mobility, as well as normal levels of testosterone. In the early stages of pregnancy, a deficiency in zinc has been directly linked to miscarriages. A lack of zinc can hinder a woman’s body from producing mature eggs that are ripe for fertilization.
Deficiencies of zinc can cause a delay or stunting of growth, frequent occurrence of infections, as well as appetite and weight loss in children. It can also lead to losses in sight and hearing, a delay in sexual maturation in men, loss of hair, loss of appetite and weight, as well as dry skin and anemia.
Food sources of zinc include oysters (74 mg/serving), beef chuck roast (7 mg/serving), crab, fortified cereals, other meats, beans, and some dairy products. Be aware that there are certain components of plant foods that can bind to the zinc and make it less bio-available, inhibiting absorption.
The RDA (Recommended Daily Allowance) for zinc is 11 mg/day for adult males and 8 mg/day for adult females. The UL (the Tolerable Upper Intake Level) is set at 40 mg/day for adults, so if one is considering supplementing their diet with zinc, it is important to know how high intakes of zinc can lead to toxicity; symptoms of acute toxicity include abdominal pain, diarrhea, nausea, and vomiting, while prolonged consumption of excessive zinc shows signs of copper deficiency. This is due to the interference of high amounts of zinc on copper absorption, which can negatively affect blood health. Overall, zinc is an important mineral for maintaining a healthy immune system and supporting reproductive function.